homo erectus； which became javaman and peking man and the like； and a later； more advanced wave of homo sapiens； whichdisplaced the first lot。 yet to accept that you must believe thathomo sapiens got so far withtheir more modern technology and then； for whatever reason； gave it up。 it was all verypuzzling； to say the least。”
as it turned out； there would be a great deal else to be puzzled about； and one of the mostpuzzling findings of all would e from thorne’s own part of the world； in the outback ofaustralia。 in 1968； a geologist named jim bowler was poking around on a long…dried lakebedcalled mungo in a parched and lonely corner of western new south wales when somethingvery unexpected caught his eye。 sticking out of a crescent…shaped sand ridge of a type knownas a lunette were some human bones。 at the time； it was believed that humans had been inaustralia for no more than 8；000 years； but mungo had been dry for 12；000 years。 so whatwas anyone doing in such an inhospitable place？
the answer； provided by carbon dating； was that the bones’ owner had lived there whenlake mungo was a much more agreeable habitat； a dozen miles long； full of water and fish；fringed by pleasant groves of casuarina trees。 to everyone’s astonishment； the bones turnedout to be 23；000 years old。 other bones found nearby were dated to as much as 60；000 years。
this was unexpected to the point of seeming practically impossible。 at no time sincehominids first arose on earth has australia not been an island。 any human beings who arrivedthere must have e by sea； in large enough numbers to start a breeding population； aftercrossing sixty miles or more of open water without having any way of knowing that aconvenient landfall awaited them。 having landed； the mungo people had then found their waymore than two thousand miles inland from australia’s north coast—the presumed point ofentry—which suggests； according to a report in the proceedings of the national academy ofsciences； “that people may have first arrived substantially earlier than 60；000 years ago。”
how they got there and why they came are questions that can’t be answered。 according tomost anthropology texts； there’s no evidence that people could even speak 60；000 years ago；much less engage in the sorts of cooperative efforts necessary to build ocean…worthy craft andcolonize island continents。
“there’s just a whole lot we don’t know about the movements of people before recordedhistory；” alan thorne told me when i met him in canberra。 “do you know that whennineteenth…century anthropologists first got to papua new guinea； they found people in thehighlands of the interior； in some of the most inaccessible terrain on earth； growing sweetpotatoes。 sweet potatoes are native to south america。 so how did they get to papua newguinea？ we don’t know。 don’t have the faintest idea。 but what is certain is that people havebeen moving around with considerable assuredness for longer than traditionally thought； andalmost certainly sharing genes as well as information。”
the problem； as ever； is the fossil record。 “very few parts of the world are even vaguelyamenable to the long…term preservation of human remains；” says thorne； a sharp…eyed manwith a white goatee and an intent but friendly manner。 “if it weren’t for a few productiveareas like hadar and olduvai in east africa we’d know frighteningly little。 and when youlook elsewhere； often wedo know frighteningly little。 the whole of india has yielded just oneancient human fossil； from about 300；000 years ago。 between iraq and vietnam—that’s adistance of some 5；000 kilometers—there have been just two： the one in india and aneandertal in uzbekistan。” he grinned。 “that’s not a whole hell of a lot to work with。 you’releft with the position that you’ve got a few productive areas for human fossils； like the greatrift valley in africa and mungo here in australia； and very little in between。 it’s notsurprising that paleontologists have trouble connecting the dots。”
the traditional theory to explain human movements—and the one still accepted by themajority of people in the field—is that humans dispersed across eurasia in two waves。 thefirst wave consisted of homo erectus； who left africa remarkably quickly—almost as soon asthey emerged as a species—beginning nearly two million years ago。 over time； as they settledin different regions； these early erects further evolved into distinctive types—into java manand peking man in asia； and homo heidelbergensis and finally homo neanderthalensis ineurope。
then； something over a hundred thousand years ago； a smarter； lither species of creature—the ancestors of every one of us alive today—arose on the african plains and began radiatingoutward in a second wave。 wherever they went； according to this theory； these new homosapiens displaced their duller； less adept predecessors。 quite how they did this has alwaysbeen a matter of disputation。 no signs of slaughter have ever been found； so most authoritiesbelieve the newer hominids simply outpeted the older ones； though other factors may alsohave contributed。 “perhaps we gave them smallpox；” suggests tattersall。 “there’s no real wayof telling。 the one certainty is that we are here now and they aren’t。”
these first modern humans are surprisingly shadowy。 we know less about ourselves；curiously enough； than about almost any other line of hominids。 it is odd indeed； as tattersallnotes； “that the most recent major event in human evolution—the emergence of our ownspecies—is perhaps the most obscure of all。” nobody can even quite agree where trulymodern humans first appear in the fossil record。 many books place their debut at about120；000 years ago in the form of remains found at the klasies river mouth in south africa；but not everyone accepts that these were fully modern people。 tattersall and schwartzmaintain that “whether any or all of them actually represent our species still awaits definitiveclarification。”
the first undisputed appearance of homo sapiens is in the eastern mediterranean； aroundmodern…day israel； where they begin to show up about 100；000 years ago—but even therethey are described （by trinkaus and shipman） as “odd； difficult…to…classify and poorlyknown。” neandertals were already well established in the region and had a type of tool kitknown as mousterian； which the modern humans evidently found worthy enough to borrow。
no neandertal remains have ever been found in north africa； but their tool kits turn up allover the place。 somebody must have taken them there： modern humans are the onlycandidate。 it is also known that neandertals and modern humans coexisted in some fashionfor tens of thousands of years in the middle east。 “we don’t know if they time…shared thesame space or actually lived side by side；” tattersall says； but the moderns continued happilyto use neandertal tools—hardly convincing evidence of overwhelming superiority。 no lesscuriously； acheulean tools are found in the middle east well over a million years ago； but scarcely exist in europe until just 300；000 years ago。 again； why people who had thetechnology didn’t take the tools with them is a mystery。
for a long time； it was believed that the cro…magnons； as modern humans in europebecame known； drove the neandertals before them as they advanced across the continent；eventually forcing them to its western margins； where essentially they had no choice but tofall in the sea or go extinct。 in fact； it is now known that cro…magnons were in the far west ofeurope at about the same time they were also ing in from the east。 “europe was a prettyempty place in those days；” tattersall says。 “they may not have encountered each other allthat often； even with all their ings and goings。” one curiosity of the cro…magnons’ arrivalis that it came at a time known to paleoclimatology as the boutellier interval； when europewas plunging from a period of relative mildness into yet another long spell of punishing cold。
whatever it was that drew them to europe； it wasn’t the glorious weather。
in any case； the idea that neandertals crumpled in the face of petition from newlyarrived cro…magnons strains against the evidence at least a little。 neandertals were nothing ifnot tough。 for tens of thousands of years they lived through conditions that no modern humanoutside a few polar scientists and explorers has experienced。 during the worst of the ice ages；blizzards with hurricane…force winds were mon。 temperatures routinely fell to 50 degreesbelow zero fahrenheit。 polar bears padded across the snowy vales of southern england。
neandertals naturally retreated from the worst of it； but even so they will have experiencedweather that was at least as bad as a modern siberian winter。 they suffered； to be sure—aneandertal who lived much past thirty was lucky indeed—but as a species they weremagnificently resilient and practically indestructible。 they survived for at least a hundredthousand years； and perhaps twice that； over an area stretching from gibraltar to uzbekistan；which is a pretty successful run for any species of being。
quite who they were and what they were like remain matters of disagreement anduncertainty。 right up until the middle of the twentieth ce